Optimizely Episerver Content Management System up to 11.21.3/12.22.0 cross site scripting

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Optimizely Episerver Content Management System up to 11.21.3/12.22.0. This affects an unknown part. Performing a manipulation results in cross site scripting. This vulnerability was named CVE-2025-27802. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Optimizely Episerver Content Management System up to 11.21.3/12.22.0. It has been classified as problematic. This affects an unknown functionality. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

The Episerver Content Management System (CMS) by Optimizely was affected by multiple Stored Cross-Site Scripting (XSS) vulnerabilities. This allowed an authenticated attacker to execute malicious JavaScript code in the victim's browser. RTE properties (text fields), which could be used in the "Edit" section of the CMS, allowed the input of arbitrary text. It was possible to input malicious JavaScript code in these properties that would be executed if a user visits the previewed page. Attackers needed at least the role "WebEditor" in order to exploit this issue. Affected products: Version 11.X: EPiServer.CMS.Core (<11.21.4) with EPiServer.CMS.UI (<11.37.5), Version 12.X: EPiServer.CMS.Core (<12.22.1) with EPiServer.CMS.UI (<11.37.3)

The weakness was presented by Kai Zimmermann. The advisory is shared at support.optimizely.com. This vulnerability is uniquely identified as CVE-2025-27802 since 03/07/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. Additional levels of successful authentication are necessary for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 11.21.4 or 12.22.1 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Content Management System

Vendor

• Optimizely

Name

• Episerver Content Management System

Version

• 11.21.0
• 11.21.1
• 11.21.2
• 11.21.3
• 12.0
• 12.1
• 12.2
• 12.3
• 12.4
• 12.5
• 12.6
• 12.7
• 12.8
• 12.9
• 12.10
• 12.11
• 12.12
• 12.13
• 12.14
• 12.15
• 12.16
• 12.17
• 12.18
• 12.19
• 12.20
• 12.21
• 12.22.0

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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